:root {
    --bg-color: #F8FAFC;
    --panel-bg: #FFFFFF;
    --text-main: #0F172A;
    --text-muted: #64748B;
    --primary: #2563EB;
    --primary-hover: #1D4ED8;
    --border-color: #E2E8F0;
    --input-bg: #F1F5F9;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius: 18px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --bg-color: #0F172A;
    --panel-bg: #1E293B;
    --text-main: #F8FAFC;
    --text-muted: #94A3B8;
    --border-color: #334155;
    --input-bg: #0F172A;
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    transition: background-color 0.3s ease, color 0.3s ease;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 2rem;
    background-color: var(--panel-bg);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: sticky;
    top: 0;
    z-index: 10;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-muted);
    margin: 0 1rem;
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
}

.nav-links a:hover {
    color: var(--text-main);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

.theme-toggle {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    transition: var(--transition);
}

.theme-toggle:hover {
    background-color: var(--border-color);
    transform: scale(1.05);
}

/* Main Container */
.main-container {
    display: flex;
    flex: 1;
    gap: 2rem;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.panel {
    background-color: var(--panel-bg);
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.panel:hover {
    box-shadow: var(--shadow-lg);
}

.left-panel {
    flex: 0 0 340px;
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

.panel-header h2 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
}

.panel-header p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.right-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.preview-header h2 {
    font-size: 1.25rem;
    font-weight: 700;
}

/* Controls */
.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.control-group label {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-main);
}

.value-display {
    color: var(--text-muted);
    font-variant-numeric: tabular-nums;
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    background: var(--border-color);
    border-radius: 3px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    transition: var(--transition);
    border: 3px solid var(--panel-bg);
    box-shadow: 0 0 0 1px var(--primary), var(--shadow-sm);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

.color-picker-wrapper {
    height: 44px;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    padding: 2px;
    background: var(--input-bg);
}

input[type="color"] {
    -webkit-appearance: none;
    border: none;
    width: 100%;
    height: 100%;
    cursor: pointer;
    padding: 0;
    background: none;
    border-radius: 6px;
}
input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}
input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 6px;
}

/* Buttons */
.button-group {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
}

.btn {
    padding: 0.75rem 1.25rem;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-family: inherit;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    flex: 1;
}

.btn-primary {
    background-color: var(--primary);
    color: #fff;
    box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.39);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
    background-color: var(--input-bg);
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--border-color);
    transform: translateY(-1px);
}

.btn-outline {
    background-color: transparent;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
}

.btn-outline:hover {
    border-color: var(--text-main);
    color: var(--text-main);
}

/* Preview Area */
.preview-area {
    flex: 1;
    background-color: var(--input-bg);
    background-image: 
        radial-gradient(var(--border-color) 1.5px, transparent 1.5px),
        radial-gradient(var(--border-color) 1.5px, transparent 1.5px);
    background-size: 24px 24px;
    background-position: 0 0, 12px 12px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 420px;
    border: 1px solid var(--border-color);
    overflow: hidden;
    position: relative;
}

.preview-area svg {
    width: 100%;
    height: 100%;
    max-width: 420px;
    max-height: 420px;
    transition: transform 0.3s ease;
}

.preview-area svg path {
    transition: d 0.4s cubic-bezier(0.4, 0, 0.2, 1), fill 0.3s ease;
}

.export-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* Footer */
.footer {
    padding: 2rem;
    text-align: center;
    background-color: var(--panel-bg);
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.875rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-links {
    display: flex;
    gap: 2rem;
    font-weight: 500;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background-color: var(--text-main);
    color: var(--bg-color);
    padding: 0.875rem 1.5rem;
    border-radius: 30px;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.toast::before {
    content: "✓";
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: #22c55e;
    color: white;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    font-size: 0.75rem;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    visibility: visible;
}